Malicious PDF — malware analysis report

Static analysis result for SHA-256 dafaa42ef5a2c598…

MALICIOUS

PDF

180.5 KB
MD5: 143acb0ba675e3d3a89fdc72c3a3a918 SHA-1: 71d7681dd0f99599347002ef154d8515abc99a95 SHA-256: dafaa42ef5a2c5986663cc60eae0830775a64acb8669c98134119f4a27723410
318 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.001 Malicious Link

Multiple critical heuristics indicate the exploitation of known PDF vulnerabilities, specifically CVE-2009-0927, CVE-2007-5659, and CVE-2008-2992, through embedded JavaScript. The extracted JavaScript streams, particularly 'legacy_pdfkit_stage_000.js', are heavily obfuscated but are flagged by ClamAV as exploit shellcode. This suggests the primary function of the PDF is to act as a dropper for malicious JavaScript, which likely downloads and executes further payloads. The confidence is high due to multiple critical heuristic firings and ClamAV detections on both the main PDF and extracted artifacts.

Heuristics 8

  • Collab.getIcon — CVE-2009-0927 critical CVE exact CVE_2009_0927
    PDF JavaScript calls Collab.getIcon — CVE-2009-0927 is a stack buffer overflow in Adobe Reader triggered by Collab.getIcon() with a crafted argument. Allows arbitrary code execution. (identified after JavaScript deobfuscation)
  • Collab.collectEmailInfo — CVE-2007-5659 critical CVE exact CVE_2007_5659
    PDF JavaScript calls Collab.collectEmailInfo — CVE-2007-5659 is a buffer overflow in Adobe Reader triggered by a long argument or heap-sprayed message field passed to Collab.collectEmailInfo(). Part of a series of Acrobat JS API exploits. (identified after JavaScript deobfuscation)
  • util.printf — CVE-2008-2992 critical CVE exact CVE_2008_2992
    PDF JavaScript calls util.printf() — CVE-2008-2992 is a stack buffer overflow in Adobe Reader triggered by a long format-specifier argument. Widely exploited in the wild after disclosure. (identified after JavaScript deobfuscation)
  • ClamAV: Pdf.Exploit.Agent-36114 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36114
  • ClamAV detection on extracted artifact critical EXTRACTED_FILE_CLAMAV
    ClamAV flagged at least one file extracted from inside this sample. Even when the wrapping document carries no AV detection of its own, a hit on the carved artifact is a strong indicator the sample is a delivery vehicle.
  • JavaScript action low PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0008_000.js
847e46bd03ed8601fe64dcb12b2982df87e06703f27b6d732e58c544c8227361
pdf-javascript-stream PDF /JS object 8 at offset 0x1E7 2687 bytes
Detection
ClamAV: Pdf.Exploit.Agent-36307
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).
legacy_pdfkit_stage_000.js
a4c12c691666475e7861cfcd0d33fc5cf0ecbe6de534af838f7b1fd550f170b9
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0xC9A 20147 bytes
Detection
ClamAV: Js.Exploit.Shellcode-18
Obfuscation or payload: likely
Carved artifact contains 11 eval/decoder/string-building token(s).